2- what is the mass of a solid steel wrecking ball of radius 15cm, knowing that the density of solid steel is 7.8x103?

Alexander calder's mobiles are an example of motion because it uses forces of wind and water.

In a set amount of time, a battery supplies 25j of energy to an electric circuit that includes two different loads. one of the loads produces 10 j of heat energy during this time interval. how much heat energy is produced by the second load in this time? explain your answer

What is the role of lenses in microscopy?